Elevator lift

ABSTRACT

A pair of lifting cylinders are arranged laterally of an elevator car to be lifted thereby; each of the cylinders comprising a stationary piston and an extensible plunger cylinder slidably carried thereon. The elevator car is supportably positioned below the upper end of the plunger cylinder for vertical movement therewith so as to permit the length of that portion of the lifting cylinder which projects above the car to be varied in accordance with height through which the car is to be lifted. The elevator car is provided with pairs of vertically spaced guide assemblies adapted to cooperate with a pair of guide rails extending vertically of the intended path of elevator travel. Each plunger cylinder is received within one pair of guide assemblies for purposes of stabilizing the elevator car and provided with a ring member on which one of the assemblies is mounted for purposes of supporting the elevator car.

D United States Patent 1111 3,613,834

72 Inventor Frank Howard Field FOREIGN PATENTS 133: vifflinia Blvd-Jamestown, 1,086,181 2/1955 France 187/17 [2]] App]. No. 853,748 Primary Examiner-Harvey C. Hornsby [22] Filed Aug. 2 19 9 Attorney-Bean 8L Bean [45] Patented Oct. 19, 1971 ABSTRACT: A pair of lifting cylinders are arranged laterally [54] ELEVATOR LIFT of an elevator canto be lifted thereby; each of the cylinders 6 Claims, 4 Drawtng Fism comprising a stationary piston and an extens1b1e plunger cylinder slidably carried thereon. The elevator car is sup- [52] US. Cl 187/17, pol-tably positioned below the upper end f the plunger 187/95 cylinder for vertical movement therewith so as to permit the [51] Int. Cl. B66b 11/04 |ength f that portion f the hftihg cylinder which projects [50] Field of Search 187/9, 17, above h car to b i d i accordance with height through 95; 212/64, 57 which the car is to be lifted. The elevator car is provided with pairs of vertically spaced guide assemblies adapted to [56] Reknnces Cited cooperate with a pair of guide rails extending vertically of the UNITED STATES PATENTS intended path of elevator travel. Each plunger cylinder is 2,214,588 9/1940 Lagerquist 187/95 received within one pair of guide assemblies for purposes of 3,182,009 5/1965 Nacband 187/8.59 stabilizing the elevator car and provided with a ring member 3,332,517 7/1967 Voser 187/95 on which one of the assemblies is mounted for purposes of 3,338,334 8/1967 Matthews 187/8.59 supporting the elevator car.

PATENTED ET 1 3. 6 1 3 .834 SHEET 10F 2 INVENTOR.

J a RIQNK HOW/7M7 FIELD @3444 Gm ATTORNEYS PATENTEnum 1s |97l 3,613,834 sum 2 OF 2 ATTORNEYS ELEVATOR LIFT BACKGROUND OF THE INVENTION Conventionally, hydraulically operated elevators are actuated by a central lifting piston, which supports an elevator car adjacent its upper end. The lifting piston is movable supported within a cylinder casing, which is sunk into the ground to a depth sufficient to permit the car to rest at ground or lower floor level when the piston is fully retracted. With this type of installation, the extent of car movement desired determines the contracted length of the piston and cylinder casing combination and thus the depth to which the cylinder casing must be sunk into the ground. Obviously, the drilling of a hole in the ground of sufficient depth to receive the cylinder casing is an expensive operation and ofttimes impossible due to the presence of underground obstacles, such as a subway.

In order to overcome the drawbacks of conventional hydraulic elevator installations, it has been proposed, as evidenced by US. Pat. No. 2,2l4,588, to employ a pair of lifting cylinder casings arranged laterally of an elevator car and disposed substantially entirely above the ground or lower floor. In this arrangement, a crosshead is mounted on the upper ends of the lifting pistons by a ball and socket connection and slings are provided for the purpose of suspending the elevator car immediately below the crosshead between the pistons. This arrangement lends itself to a relatively inexpensive two floor lift installation for the reason that no drilling is required and the only digging necessary is that required to form a relatively shallow pit below the car to accommodate hydraulic liftings and structural footings. However, when more than a two floor lift installation is desired, the cylinder casings must again be sunk into the ground a distance sufficient to accommodate the added piston-cylinder casing length required for servicing additional upper floors. Otherwise, the length of the platform supporting slings would become excessive and unacceptable binding of the piston-cylinder casing would likely be encountered.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hydraulically operated elevator car-lifting arrangement by which the car may be lifted through two or more floors by lifting cylinders disposed substantially entirely above the ground or lower floor.

It is a further object of the present invention to provide a simplified elevator lift and car installation, whereby the parts thereof may be readily assembled within the narrow confines of an elevator shaft.

The present invention employs a pair of lifting cylinders arranged laterally of an elevator car to be lifted thereby; each of the cylinders comprising a stationary piston, which is pivotally affixed to a supporting structure, such as ground, and a plunger cylinder, which is slidably carried by the piston. The elevator car is supportably positioned adjacent the lower end of the plunger cylinder for vertical movement therewith, so as to permit the length of that portion of the lifting cylinder which projects above the car to be varied in accordance with height through which the car is to be lifted. The elevator car is provided with pairs of vertically spaced guide assemblies adapted to cooperate with a pair of guide rails extending vertically of the intended path of elevator travel. Each plunger cylinder is loosely received within a pair of the guide assemblies for purposes of stabilizing the elevator car and provided with a ring member on which one of the assemblies is mounted for purposes of supporting the elevator car.

Fabrication of the guide assemblies and association thereof with the elevator car and plunger cylinders is facilitated by forming the car with a pair of horizontally arranged, car platform supporting planks and a pair of horizontally arranged crossheads, which are joined to a pair of vertically extending stiles in a straddling relationship adjacent the lower and upper ends thereof, respectively.

One-half of the elevator platform is carried by each of the planks, such that the platform is completed when the planks are affixed to the stiles. Ends of the planks and crossheads which project beyond the respective stiles form a part of the guide assemblies. Each pair of vertically spaced guide assemblies is completed by a pair of vertically rising guide rail engaging shoe supporting plates, which are afi'lxed one to each of the projecting ends of the crossheads and planks in a spaced relationship to their associated stile, and a pair of horizontally arranged lifting or guide plates, which are affixed one to each of the projecting ends of the crossheads and planks so as to extend between their associated stile and guide rail engaging shoe supporting plate. The lifting plates of each pair of assemblies are provided with vertically aligned apertures adapted to loosely receive the plunger cylinder to be associated with such pair of assemblies. Preferably, the planks, crossheads, stiles, shoe supporting plates and lifting plates are bolt connected to facilitate assembly thereof at the point of installation. The ring members carried by the plunger cylinders are adapted to engage beneath one lifting plate of each pair of assemblies for the purpose of supporting the elevator car for vertical movement.

By loosely associating the guide assemblies with the plunger cylinders and by pivotally affixing the lifting cylinder pistons to the ground, the elevator car and lifting cylinders are permitted to orient themselves with respect to each other in order to compensate for any slight shift or movement of the elevator car guide rails occasioned by settling of the building structure.

DRAWINGS FIG. 1 is a perspective view of illustrating the elevator lift according to the present invention installed in a building, wherein the elevator car is at rest at its ground or lower floor level;

FIG. 2 is a fragmentary side elevational view of the elevator lift shown in FIG. 1;

FIG. 3 is a sectional view taken along the line 3-3 in FIG. 2; and

FIG. 4 is a fragmentary view illustrating the lifting cylinders fully extended to position the elevator car at its uppermost floor level.

DETAILED DESCRIPTION Referring to FIG. 1, it will be understood the elevator lift of the present invention, which is generally designated as l, is adapted to be installed within a well 2 of a building for the purpose of lifting an elevator car 3 between a ground or lower level floor 4 and upper level floors 5 and 6. While the invention is shown in FIG. 1 as being employed in a three floor building, it will be understood that its utility is not limited thereto.

As is conventional, a pair of vertically rising T-shaped, elevator car guide rails 8, 8 are secured to the building walls defining well 2 by suitable clamps 9, 9.

Also, as is conventional, a shallow pit 10 is provided below well 2 for the purpose of housing hydraulic drive equipment, not shown, to be employed in controlling operation of lift 1. The hydraulic drive equipment and controls therefor, which if desired may be of the type disclosed in US. Pat. No. 2,214,588, form no part of the present invention. However, they are shown for purpose of reference as including a supply and exhaust conduit 12 for a driving fluid, which is branched at 13, 13'. It will be understood that while oil is preferably employed as the driving fluid, any other suitable fluid may be employed, as desired.

Lift 1 includes a pair of identically constructed lifting cylinders 15, 15, which are arranged laterally of car 3 and bottom supported within pit 10 on bearing plates 16, 16. It will be understood that lifting cylinders 15, 15' include stationary hollow pistons 18, 18' into which are connected branched conduits 13, 13'; and plunger cylinders 19, 19, which are slidably mounted on pistons 18, 18', and loosely received within pairs of vertical spaced elevator car mounted guide assemblies 21, 22 and 21 22, respectively. Suitable means, not shown, may be carried by plunger cylinders 19, 19' for the purpose of providing a sliding fluid seal with the outer surfaces of pistons 18, 18'. Preferably, pistons 18, 18 are connected to bearing plates l6, 16' by pivot pins 24, 24', so as to permit slight pivotal movement of lifting cylinders l5, in a direction normal to the plane defined by guide rails 8, 8. Plunger cylinders 19, 19 have weld affixed thereto ring members 26, 26, which are preferably disposed immediately adjacent the lower ends thereof and employed to support car 3 for vertical movement therewith in the manner to be described. it will then be understood that one or more projecting lugs or the like, not shown, may be substituted for ring members 26, 26, and thus the term ring members is used herein generically to mean members projecting radially from the plunger cylinders for the purpose of supporting the elevator car in the manner to be described.

Elevator car 3 is preferably of a construction which admits to the assembly thereof within the narrow confines of well 2. In the main, car 3 includes a pair of horizontally disposed planks or lower members 28, 29 and a pair of horizontally disposed crosshead or upper flange members 32, 33, which are suitably joined, as by bolts 34 shown only in FIG. 3, to a pair of vertically rising stiles 36, 36 in a straddling relationship adjacent the lower and upper ends thereof, respectively.

Planks 28, 29 serve to carry elevator platform halves 38, 39, such that the elevator platform may be completely assembled when planks 28, 29 are bolted to stiles 36, 36'. If desired, suitable tension rods 40 may be provided to assist in rigidifying the elevator platform, and framework angle irons 41 employed to facilitate mounting of elevator roofing and sidewall panels, not shown.

It will be understood that guide assemblies 21-22' are formed in part by the ends of planks 28, 29 and crossheads 32, 33, which project outwardly beyond stiles 36, 36, respectively. Referring particularly to FIGS. 2 and 3 in the case of assemblies 21, 22, it will be understood that each pair of guide assemblies is completed by a pair of vertically rising mounting plates 43, 44 and a pair of horizontally disposed lifting or guide plate members 47, 48, which are fixed by bolts 45 and 50 to the projecting ends of planks 28, 29 and crossheads 32, 33, respectively. Suitable guide rails engaging means, such as conventional guide shoes 51, 52, may be affixed to mounting plates 43, 44 by bolts 53. Planks 28, 29; crossheads 32, 33; stiles 36, 36' and mounting plates 43, 44 are preferably in the form of U-shaped channel members so as to both facilitate interconnection thereof and add rigidity to the assembled structure. Lifting plates 47, 48 are provided with vertically aligned apertures 54, which are adapted to loosely receive plunger cylinder 19.

in order to comply with prevailing building codes, which require that hydraulically actuated elevator cars be platform supported, car 3 is preferably supported for movement with plunger cylinders 19, 19' by engagement of ring members 26, 26' with lifting plates 47, 47. Also, this arrangement greatly facilitates assembly of the elevator car and guide assemblies, since they may be built up upon lifting plates 47, 47 after the latter have been positioned on ring members 26, 26'. However, if desired, ring members 26, 26 may be employed to directly support upper guide assemblies 22, 22. In any case, it is preferable to provide one of more clamps 55, which are releasably secured by bolts 50 and adapted to prevent separation of the ring members and lifting plates should car 3 encounter an obstacle during downward movement thereof. Clamps 55 also prevent vibration which might otherwise result due to the loose fit between the guide assemblies and the plunger cylinders.

It will be apparent that by loosely associating guide assemblies 21-22 with plunger cylinders 19, 19 and pivotally mounting pistons 18, 18', the elevator car and lifting cylinders are permitted to the reoriented when necessary to compensate for slight 9, or movements guide rails 8, 8', which might be occasioned by settling of 1, building structure after installation of the elevator. With this arrangement, the possibility of bending the lifting cylinders during use is greatly reduced.

Referring now to FIGS. 1 and 2 it will be understood that car 3 is positioned at its ground or lower floor level, when lifting cylinders 15, 15' are substantially fully be In this condition the upper ends 18a, 18a of the pistons are disposed closely adjacent the upper ends 19a, 19a of the plunger cylinders. When driving fluid is introduced into pistons 18, 18', car 3 may be raised to the uppermost floor to be serviced thereby, that is, floor 6 in the installation illustrated. When car 3 is so positioned, cylinders 15, 15' are substantially fully extended so as to raise the lower ends 1%, 19b of the plunger cylinders to a point closely adjacent the upper ends 18a, 18a of the stationary pistons, as shown in FIG. 4 in the case of lifting cylinder 15.

It will be understood that a particularly important feature of the present invention is to interconnect the plunger cylinders to the elevator car so as to permit the lifting cylinders to extend freely above such car. By this arrangement, the lifting cylinders may be both disposed substantially completely above ground or the lower level served by the car and be of a length required to raise the car through any desired distance. Further, since the car is supportably carried below the upper end of the plunger cylinder, the effective load supporting column length of the lifting cylinders is always at a minimum. Thus, greater car loads may be supported by a given pair of lifting cylinders, than would be possible if, as with conventional installations, the elevator car were supported only adjacent the upper end of such cylinders.

in the three fioor installation illustrated, the contracted length of the lifting cylinders would be slightly in excess of the distance between floors 6 and 4, whereas when extended their overall length would be approximately double their contracted length. Any desired arrangement may be provided on the roof of the building in which the elevator is installed to accommodate and provide a weather protection enclosure for the plunger cylinders when the lifting cylinders are fully extended.

While only the preferred embodiment of my invention has been described in detail, it will be understood that various changes in and modification of my invention may be employed without fully departing from the spirit thereof. in this respect, the guide assemblies may be of welded construction. Further, where shifting of guide rails is not a critical consideration, the guide assemblies or the elevator car may be welded to the plunger cylinders.

I claim:

1. An elevator installation for servicing lower floor level and at least one upper fioor level, including in combination:

an elevator car;

a pair of parallel guide rails extending vertically between said floor levels;

a pair of vertically extending lifting cylinders extensible for elevating said car between said floor levels, said cylinders being arranged one adjacent each of a pair of opposite sides of said car and being disposed substantially entirely above said lower level, each of said cylinders including a piston and a plunger cylinder slideably supported thereon for extensible movement with respect thereto;

means for supporting said pistons adjacent said lower floor level for pivotal movement about a substantially common horizontally disposed pivot axis lying substantially within a vertical plane defined by said guide rails;

two pairs of vertically aligned upper and lower guide assemblies carried by said car one pair adjacent each of said opposite sides thereof for association one pair with each of said plunger cylinders, said upper and lower guide assemblies being positioned respectively adjacent the top and bottom of said car, said assemblies including follower means engageable with said guide rails maintaining said car sides substantially centered relative to said guide rails during vertical movements of said car between said floor levels, said upper and lower guide assemblies of each said pair carrying means bounding an associated plunger cylinder adjacent vertically spaced portions thereof for loosely maintaining said associated plunger cylinder substantially centered relative to an associated side of said car; and

means fixed to a projecting radially from each of said plunger cylinders intermediate upper and lower ends thereof, said projecting means being adapted to supportingly engage at least one said assemblies of each said pair of assemblies to thereby support said car on said plunger cylinders intermediate the upper and lower ends thereof, the upper ends of said plunger cylinders extending freely above said upper guide assemblies and said car, thereby to permit said cylinders to be of a length sufficient when extended to raise said car between said floor levels.

2. An elevator installation for servicing a lower floor level and at least one upper floor level, including in combination:

an elevator car;

a pair of vertically extending lifting cylinders extensible for elevating said car between said floor levels, said cylinders being arranged one adjacent each of a pair of opposites sides of said car and being disposed substantially entirely above said lower level, each of said cylinders including a stationary piston fixed adjacent said lower floor level and a plunger cylinder slideably supported thereon for extensible movement with respect thereto;

a pair of parallel guide rails extending vertically between said floor levels;

two pairs of vertically aligned upper and lower guide assemblies carried by said car one pair adjacent each of said opposite sides thereof, said upper and lower guide assemblies being positioned respectively adjacent the top and bottom of said car, said assemblies including follower means centered relative to said opposite sides of said car for cooperating with said rails to guide said car during vertical movement between said floor level, said plunger cylinders extending vertically one through each of said pair of assemblies, said upper and lower guide assemblies of each said pair of assemblies having means for positioning an associated plunger cylinder to extend vertically intermediate said follower means of said assemblies and an associated side of said car and maintaining said associated plunger cylinder substantially centered relative to said associated side of said car, whereby said opposite sides of said car and said rails and said follower means and said plunger cylinders are vertically bisected by a substantially common plane; and

means for supporting at least one of said assemblies of each said pair of assemblies on said plunger cylinders intermediate the upper and lower ends thereof thereby to support said car, the upper ends of said plunger cylinders extending freely above said upper guide assemblies and said car, thereby to permit said cylinders to be of a length sufficient when extended to raise said car between said floor levels.

3. An elevator installation according to claim 2, wherein each said positioning means defines an aperture for loosely receiving an associated plunger cylinder, and said pistons are pivotally supported adjacent the lower ends thereof for movement at least about a substantially common horizontally disposed pivot axis extending between said opposite sides of said car and lying substantially within said plane.

4. An elevator installation for servicing a lower floor level and at least one upper floor level, including in combination:

an elevator car, said car including a pair of parallel vertically extending stiles disposed in a centered relationship one adjacent each of a pair of opposite sides of said car, a pair of parallel horizontally disposed crossheads and a pair of parallel horizontally disposed elevator car platform supporting planks, said crossheads and said planks being fixed in a straddling relationship to upper and lower ends of said stiles, respectively, such that said crossheads and planks are in vertical alignment and define two pairs of upper and lower end portions projecting outwardly beyond said stiles relative to said opposite sides;

a pair of vertically extending lifting cylinders extensible for elevating said car between said floor levels, said cylinders being arranged one adjacent each of said opposite sides of said car and being disposed substantially entirely above said lower level, each of said cylinders including a stationary piston fixed adjacent said lower floor level and a plunger cylinder slideably supported thereon for extensible movement with respect thereto;

a pair of guide rails extending vertically between said floor levels;

follower means mounted one on each of said end portions in a horizontally spaced relationship-to said stiles, said follower means cooperating with said rails to guide said car during vertical movement thereof between said floor levels while maintaining said opposites sides of said cars substantially centered relative to said rails;

ring members fixed to and projecting radially from each of said plunger cylinders; and

two pairs of upper and lower plate members mounted one plate member on each of said end portions and extending horizontally intermediate said follower means to said stiles, each of said plate members being apertured t positionally receive one of said plunger cylinders therethrough thereby to maintain said plunger cylinders intermediate said stiles and said follower means and in a substantially centered relationship relative to said opposite sides of said car, said ring members supportingly engaging at least one of said upper and lower plate members of each of said pairs of members about said apertures thereof, and said plunger cylinders having the upper ends thereof extending freely above said car, thereby to permit said cylinders to be of a length sufficient when extended to raise said car between said floor levels.

5. An elevator installation according to claim 4, wherein said plunger cylinders are loosely received within said plate member apertures, said ring members are weldfixed to said plunger cylinders immediately adjacent the lower ends thereof and adapted to supportingly engage lower plate members of said pair of members, and said pistons are supported adjacent the lower ends thereof for pivotal movement at least about a substantially common axis extending horizontally between said opposite sides of said car and lying substantially within a plane vertically bisecting said opposite sides of said car and said rails and said follower means and said plunger cylinders,

6. An elevator installation according to claim 4, wherein said elevator car platform is of two part construction having parts thereof fixedly mounted one on each of said planks, whereby said platform is completed when said planks are fixed to said stiles as aforesaid.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,613,834 Dated October lg, 1971 Inventor(s) Frank Howard Field It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 3, "movable" should read movably Column 3, line 22, after "lower" insert flange line 64, "of" should read or line 74, "the" should read be line 75, "9" should read displacements line 75, after "movements" insert of Column 4, line 1, "1" should read the line 6, "he" should read retracted. Column 5, line 7, "a" should read and line 10, after-"one" insert of line 23, "opposites", should read opposite line 38, "level" should read levels Signed and sealed this 24th day of October 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents powso (0459) USCOMM-DC wave-Poo & U 5 GOVERNMENT PRINTING OFFICE 9.9 0-556-33. 

1. An elevator installation for servicing lower floor level and at least one upper floor level, including in combination: an elevator car; a pair of parallel guide rails extending vertically between said floor levels; a pair of vertically extending lifting cylinders extensible for elevating said car between said floor levels, said cylinders being arranged one adjacent each of a pair of opposite sides of said car and being disposed substantially entirely above said lower level, each of said cylinders including a piston and a plunger cylinder slideably supported thereon for extensible movement with respect thereto; means for supporting said pistons adjacent said lower floor level for pivotal movement about a substantially common horizontally disposed pivot axis lying substantially within a vertical plane defined by said guide rails; two pairs of vertically aligned upper and lower guide assemblies carried by said car one pair adjacent each of said opposite sides thereof for association one pair with each of said plunger cylinders, said upper and lower guide assemblies being positioned respectively adjacent the top and bottom of said car, said assemblies including follower means engageable with said guide rails maintaining said car sides substantially centered relative to said guide rails during vertical movements of said car between said floor levels, said upper and lower guide assemblies of each said pair carrying means bounding an associated plunger cylinder adjacent vertically spaced portions thereof for loosely maintaining said associated plunger cylinder substantially centered relative to an associated side of said car; and means fixed to a projecting radially from each of said plunger cylinders intermediate upper and lower ends thereof, said projecting means being adapted to supportingly engage at least one said assemblies of each said pair of assemblies to thereby support said car on said plunger cylinders intermediate the upper and lower ends thereof, the upper ends of said plunger cylinders extending freely above said upper guide assemblies and said car, thereby to permit said cylinders to be of a length sufficient when extended to raise said car between said floor levels.
 2. An elevator installation for servicing a lower floor level and at least one upper floor level, including in combination: an elevator car; a pair of vertically extending lifting cylinders extensible for elevating said car between said floor levels, said cylinders being arranged one adjacent each of a pair of opposites sides of said car and being disposed substantially entirely above said lower level, each of said cylinders including a stationary piston fixed adjacent said lower floor level and a plunger cylinder slideably supported thereon for extensible movement with respect thereto; a pair of parallel guide rails extending vertically between said floor levels; two pairs of vertically aligned upper and lower guide assemblies carried by said car one pair adjacent each of said opposite sides thereof, said upper and lower guide assemblies being positioned respectively adjacent the top and bottom of said car, said assemblies including follower means centered relative to said opposite sides of said car for cooperating with said rails to guide said car during vertical movement between said floor level, said plunger cylindeRs extending vertically one through each of said pair of assemblies, said upper and lower guide assemblies of each said pair of assemblies having means for positioning an associated plunger cylinder to extend vertically intermediate said follower means of said assemblies and an associated side of said car and maintaining said associated plunger cylinder substantially centered relative to said associated side of said car, whereby said opposite sides of said car and said rails and said follower means and said plunger cylinders are vertically bisected by a substantially common plane; and means for supporting at least one of said assemblies of each said pair of assemblies on said plunger cylinders intermediate the upper and lower ends thereof thereby to support said car, the upper ends of said plunger cylinders extending freely above said upper guide assemblies and said car, thereby to permit said cylinders to be of a length sufficient when extended to raise said car between said floor levels.
 3. An elevator installation according to claim 2, wherein each said positioning means defines an aperture for loosely receiving an associated plunger cylinder, and said pistons are pivotally supported adjacent the lower ends thereof for movement at least about a substantially common horizontally disposed pivot axis extending between said opposite sides of said car and lying substantially within said plane.
 4. An elevator installation for servicing a lower floor level and at least one upper floor level, including in combination: an elevator car, said car including a pair of parallel vertically extending stiles disposed in a centered relationship one adjacent each of a pair of opposite sides of said car, a pair of parallel horizontally disposed crossheads and a pair of parallel horizontally disposed elevator car platform supporting planks, said crossheads and said planks being fixed in a straddling relationship to upper and lower ends of said stiles, respectively, such that said crossheads and planks are in vertical alignment and define two pairs of upper and lower end portions projecting outwardly beyond said stiles relative to said opposite sides; a pair of vertically extending lifting cylinders extensible for elevating said car between said floor levels, said cylinders being arranged one adjacent each of said opposite sides of said car and being disposed substantially entirely above said lower level, each of said cylinders including a stationary piston fixed adjacent said lower floor level and a plunger cylinder slideably supported thereon for extensible movement with respect thereto; a pair of guide rails extending vertically between said floor levels; follower means mounted one on each of said end portions in a horizontally spaced relationship to said stiles, said follower means cooperating with said rails to guide said car during vertical movement thereof between said floor levels while maintaining said opposites sides of said cars substantially centered relative to said rails; ring members fixed to and projecting radially from each of said plunger cylinders; and two pairs of upper and lower plate members mounted one plate member on each of said end portions and extending horizontally intermediate said follower means to said stiles, each of said plate members being apertured t positionally receive one of said plunger cylinders therethrough thereby to maintain said plunger cylinders intermediate said stiles and said follower means and in a substantially centered relationship relative to said opposite sides of said car, said ring members supportingly engaging at least one of said upper and lower plate members of each of said pairs of members about said apertures thereof, and said plunger cylinders having the upper ends thereof extending freely above said car, thereby to permit said cylinders to be of a length sufficient when extended to raise said car between said floor levels.
 5. An elevator installation according to claim 4, wherein said pLunger cylinders are loosely received within said plate member apertures, said ring members are weldfixed to said plunger cylinders immediately adjacent the lower ends thereof and adapted to supportingly engage lower plate members of said pair of members, and said pistons are supported adjacent the lower ends thereof for pivotal movement at least about a substantially common axis extending horizontally between said opposite sides of said car and lying substantially within a plane vertically bisecting said opposite sides of said car and said rails and said follower means and said plunger cylinders.
 6. An elevator installation according to claim 4, wherein said elevator car platform is of two part construction having parts thereof fixedly mounted one on each of said planks, whereby said platform is completed when said planks are fixed to said stiles as aforesaid. 